26.10.2014 Views

parks victoria technical series marine natural values study vol 2 ...

parks victoria technical series marine natural values study vol 2 ...

parks victoria technical series marine natural values study vol 2 ...

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Parks Victoria Technical Series No. 79<br />

Flinders and Twofold Shelf Bioregions Marine Natural Values Study<br />

Wilsons Promontory MNP has two distinct shallow subtidal reef assemblages, high exposure<br />

in the west and south, and low exposure in the east. Point Hicks and Cape Howe MNP<br />

shallow subtidal reefs are highly exposed and have varied structure, providing a wide range<br />

of habitats. The shallow subtidal reef in the Beware Reef has seaweed, invertebrate and fish<br />

communities that are distinctly different to the other reefs in Twofold Shelf MPAs. The deep<br />

reefs in both the bioregions have a dense and often spectacular cover of epifauna,<br />

especially sponges, stalked ascidians, soft corals, sea anemones, zooanthids gorgonians<br />

and sea whips, and abundant fish life.<br />

Subtidal soft sediment is a dominant habitat in all the MPAs but detailed knowledge of its<br />

flora and fauna is restricted to shallow waters, except for Point Hicks and Cape Howe MNPs.<br />

Sediments are predominantly inhabited by infauna (small crustaceans and worms that<br />

burrow into the sand), sponges and bottom-dwelling skates and rays. Deep water sediments<br />

in Point Hicks and Cape Howe MNPs have extensive beds of sessile invertebrates,<br />

predominately sponges and green algae Caulerpa.<br />

Seagrass beds are found in sheltered bays, Heterozostera in Oberon Bay and Amphibolis<br />

and Halophila in Waterloo Bay in Wilsons Promontory MNP. Many species of fish are<br />

associated with these beds such as wide-bodied pipefish Stigmatopora nigra, spotted<br />

pipefish S. argus, slender weed whiting Siphonognathus attenuatus and weedfish<br />

Heteroclinus spp. and Cristiceps spp. Seagrass beds are not a feature of the Twofold Shelf<br />

bioregion.<br />

All the MPAs support species of high conservation significance. They provide important<br />

feeding and roosting habitat for many threatened shore and sea birds, from 17 species in<br />

Beware Reef MS and up to 38 in Cape Howe MNP. They are also important for many<br />

migratory birds, from 7 species in Wilsons Promontory MNP to 24 in Cape Howe MNP.<br />

Numerous species are found at the limit of their distribution range within individual MPAs. In<br />

Wilsons Promontory MNP over 126 species, including algae, invertebrates and fish, are<br />

believed to be at the edge of their distributional range, whilst none are known from Ninety<br />

Mile Beach MNP. Fourteen are believed to be at the edge of their range in Point Hicks MNP,<br />

17 in Beware Reef MS and 38 in Cape Howe MNP.<br />

The humpback whale Megaptera novaeangliae, threatened southern right whale Eubalaena<br />

australis and threatened New Zealand fur seal Arctophoca forsteri are found in the waters of<br />

both bioregions. The southern right whale E. australis has been observed to calve in Cape<br />

Howe and Wilsons Promontory MNPs. Five listed <strong>marine</strong> reptiles: loggerhead turtle Caretta<br />

caretta, green turtle Chelonia mydas, Pacific ridley Lepidochelys olivacea, leatherback turtle<br />

Dermochelys coriacea, and yellow-bellied sea snake Pelamis platurus occur as warm water<br />

vagrants in the bioregions. The whale shark Rhincodon typus east coast range extends to<br />

Point Hicks MNP. The islands surrounded by Wilsons Promontory MNP, particularly<br />

Kanowna in the Anser Group, are breeding colonies of little penguins Eudyptula minor,<br />

Australian fur seals A. pusillus doriferus, and a small colony of New Zealand fur seals A.<br />

forsteri. The MNP is also a nationally significant area for the recovery of great white shark<br />

Carcharodon carcharias populations. In Ninety Mile Beach one species of crab, Halicarcinus<br />

sp MoV746 and in Point Hicks one mollusc, the welk Fax molleri, are presumed to be<br />

endemic to the MNPs. Cape Howe MNP is an important foraging area for a significant<br />

breeding colony of little penguins E. minor from neighbouring Gabo Island. The state<br />

vulnerable New Zealand fur seal A. forsteri has also been recorded breeding in the MNP.<br />

The southern elephant seal Mirounga leonina has been recorded in Beware Reef MS.<br />

The introduction of foreign species or <strong>marine</strong> pests, by recreational or commercial vessels,<br />

threatens the integrity of <strong>marine</strong> biodiversity. The New Zealand screw shell Maoricolpus<br />

roseus has been recorded in high densities on the subtidal sediment of Point Hicks MNP.<br />

The introduced green shore crab Carcinus maenas is presumed to occur on the intertidal<br />

iii

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!